A wide variety of road grader implements are known in the prior art, and include implements with dual blades of adjustable inclination angle allowing both sides of a crowned road surface to be graded in one pass, and/or blades of adjustable working position or length to increase the effective overall working width of the implement during a single pass.
Examples of bladed implements with such blade adjustments can be found in U.S. Pat. Nos. 1,537,091, 2,050,282, 5,427,185 and 6,308,785 and in U.S. Patent Application Publication No. 2006/0118313. Other blade equipped implements for grading or other ground working or ground clearing operations can be found in Canadian Patent 2448635, U.S. Patent Application Publication No. 2007/137872, and U.S. Pat. Nos. 0,987,803, 1,093,814, 1,339,548, 1,381,709, 1,507,552, 1,756,329, 2,312,255, 2,615,264, 2,787,846, 3,203,120, 4,700,786, 5,199,196, 5,330,287, 5,515,623, 5,890,546 6,119,792, 6,283,225, 6,419,030, 6,419,030 and 7,600,576
However, there remains room for improvements and alternatives to these prior designs.